Six Inch Shelf Bracket

thingiverse

I required simple shelf brackets to hold up shelves made of 2x8's. These are 150mm x 150mm x 15mm right angle brackets, close enough to my target of 6 inches. The four holes are 4mm on the sides that touch the wall and 7mm on the entry sides; this allows for my particular drill bit & screw combo. I printed in black Hatchbox PLA at 0.2mm layer height, 2 wall lines, 4 top/bottom layers, and 20% infill for testing purposes. I will likely go up to 50% to make these bulletproof later. It took 5 hours to print with fairly slow print settings for nicer quality. I plan to use these brackets "raw" and unfinished except for cleaning any stringing or what-have-you. If I end up liking the design and it holds up well, I will dump more files including versions without screw holes, with screw holes, and the objects themselves in Tinkercad so the community can remix hole placement/size/etc. My original Cura settings for testing are included as screenshots. As a note: I've found a "hack" for countersinking screws in 3D printed parts when using "countersink" or "bugle head" screws. I make the screw hole just large enough to fit the shank/threads through and then use a cordless drill to spin the screw in place long enough for friction to melt the PLA and let it conform perfectly to the screw head. This takes seconds and has produced pretty solid results with no failures. UPDATE 1/27/2020: I like these brackets, but ended up scaling them up by 2 or 3 percent to fit some other screws I was using. I will dump the Tinkercad model and instructions sometime this week when I get a chance.